"The cast is awesome. So positive. Make the process fun. I'm excited," he Tweeted on Wednesday. "Laughed all day today but gonna be a lot of work. We ready!"

As previously reported on AccessHollywood.com, the "As Long As You Love Me" singer, 18, served as a musical guest on the late night comedy back in 2010 and has since also appeared in a few sketches and a digital short.

Justin joins a long line of musicians who have braved the legendary NBC stage as both the musical guest and host, including (most recently) Bruno Mars, Elton John, Justin Timberlake, Taylor Swift, Mick Jagger, Britney Spears, Jennifer Lopez and more.